Web drier



M. E. HANSON Oct. 30, 1945.

WEB DRIER A wllrnvillldnlll Filed May 15, 1945 Mz'lon E'. 'Hans on Patented Oct. 3 0, 1945 r WEBDRIERMk p vMilton E. Hanson, Haddonfield, N. JJ, assgnor to B. F. Sturtevant Compan Boston, Mass. I

, Application May .15, 1943, serial No. 487.163

(ci. 's4- 4158) y 1o claims.

This invention relates to web driers and relates more particularly to tenter frame driers for drying cloth. f 1

The usual tenter frame driers for drying cloth employ nozzles located above and below the cloth and which blow the drying air against the cloth.

This requires a large amount of duct work and a large number of nozzles. Furthermore, the dry- .ing is vuneven .since the drying action is more effective under the nozzles than between them. To compensate for the uneven drying, it has been the practice to force very large volumes of :air

`through the nozzles.

In a drier embodying this invention no nozzles nor associated ducts are used and instead of blowing the drying air against the cloth, itIis drawn through by suction from a plurality of fan-heater units located underneath the tenter'frames. The fan-heater units are compact and relatively, inexpensive and any desired number may be placed alongside each other to make up a drier of any desired size or length. Their use results? in a lower, less expensive-drier house and in a saving in fan horsepower and steam. Y

An object of the invention is to improve the drying of cloth in tenter frame driers. I

Other objects of the invention are to simplify tenter frame driers and to reduce their installation cost and operating expense.V I I The invention will now be described `with reference to the drawing, of which: v A

Fig.. .1 is a cross section through a tenter `frame .drier embodying this invention, `and Fig. 2 is a sectional view taken along the lines 2-2 of Fig. 1.

The usual parallel chains 5 resting uponfthe usual guide rails 6 are employed. These chains have the usual clips 'I for engaging the outer edges of the cloth web 8. The rails 6 are 'movable towards and from each other on the base 4 for accommodating different cloth widths. The chains travel continuously through the drier, bringing the moist cloth in at one end and carrying the dry cloth out the opposite end.

The baIe walls 9 and 10 extend under the conveyor and are spaced apart to provide a central opening II for the the cloth.

The steam heaters I2 are placed under the walls i 9 and are connected by the ducts I3 with the shrouds I4 of the propeller' fans I5. The fans I5 are rotated through the shafts I 6 by the electric motors H which are placed outside the building so as to be out of the heated air.

. The heaters I2 preferably are made up of a plus passage of air drawn through p 'ralitycf iinned tubesl and are connected `to the `steam supply header I8 and to the condensate return header I9i y y t t The baiiie `walls YIIJ havepivoted to their outer ends, the dampers 20 which in fully closed positioncontact the side wall 2l `of the drier house asillustrated by the full lines of Fig. 1. 1n the fullf openposition" illustrated by the dashed lines of Fig. `1 the `dampers` permit air drawn bythe fans I5 to by-pass the cloth 8.` The dampers are connected by thewire or cord 22 `which runs over the pulleys'f23, to the balance weights 211.` As will be explained, the dampers :are Aadjusted to `cornpensate for different thicknesses and weights of cloth by by-passing drying air around `the cloth.

The drier has the ireshai-r inlet`25 and the exhaust air outlet stack 26. The stack `26 has the fan 21 driven by the motor 28 mounted therein I the. air vioekchaxnber 29 through the openings in its two ends where the `cloth enters andleaves, and this prevents the escape of drying air through these openings. t

The rails 6 `have attached thereto the plates 3| which extend therebeneath and which contact the baiie walls 9 and I0. These plates form air seals as the rails are moved toaccommodate diierent widths of cloth, and prevent airfrom beingdrawn bythe fans I5, between the railsY 6 and the walls 9 and i0 in a path by-passing the cloth.. y

In operation, the fans I5 draw air through the clothl S'as .indicated by the arrows of Fig. 1. The heaters 'i2 `heat this air whichis continuously recirculated.through the cloth andrheaters. `As is customary suiicient'air is exhausted through the stack A26 andlsufcient make-up air is drawn into the vdrier through the inlet 25 formaintaining suii'iciently low humidities in the air for proper drying. Y f

The `fans I5 provide pressure above the cloth and on the upper sides of the dampers andprovide Asuction under the cloth and on the undersides of the dampers. For light weight cloth the air pressure upon 4its upper surface could be too great tending to stretchit. The dampers 20 in such ycases would be .adjusted to .by-pass` sufficientair around the cloth to provide less differences in pressure between the upper and the lower sides of the cloth,V l

The wall 35 extends the length of the drier and prevents the drying air from nowing around the sides of the units and into the inlets of the fans.

Fig, 2 illustrates a number of identical drying units embodying this invention placed alongside each other. It is believed to be apparent that any size drier that may be desired can be constructed using these units.

Otherrstructural advantages are that savings in heavy and expensive-sheet metal are accomplished of eliminating the ducts and nozzles usually employed in web driers; the drier house may be lower and smaller than prior equivalent drier houses; the heavy supporting structures for the usual overhead ducts and nozzles are eliminated,

and the weight and amountoi apparatus required, is less.

Functional advantages of this invention are web to be dried through the drier, rails for supporting the conveyors and a base for slidably supporting the rails, the combination of a pair `"of spaced, substantially horizontal baiiles under said base, an air heater under one of said baies, a fan under said one of said bames, and means forming an air passage including said web, the

' space between said baffles, said heater'and said that all areas of the cloth are continuously acted upon during its passage through the drier. The drying is more effective since the drying air is drawn completely through the cloth. With the prior systems using nozzles, the cloth was acted upon only under the nozzles with so much. space between the nozzles that the drying between them was much less eiective. Lower air pressures are required resulting in decreased power costs. Complete access to the cloth surface is'gained for inspection and regulation purposes. Both sideslof the cloth are accessible.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, as modifications thereof may be suggested by those skilled in the art without departure from the essence of the .invention. Y

What is claimed is: 1. In a-tenterl frame, webdrier having a housing containing spaced webV to be dried through the drier, rails for supporting the conveyors and a base for slidably supporting the rails, `the vcombination of a pair of spaced, substantially horizontalrbaiiles under said base,- me'ans forming an air seal between said rails and baffles, an air heater under one of said bailies, a fan under said one of said baiiles, and means forming an air passage including said web, the space between saidbaiiles, said heater and said fan int series, said fan recirculating air through said passage. Y Y

-2;-In a tenter frame, web drier having a housingV containing spaced conveyors for carrying a web to be dried through thedrier, rails for supporting thek conveyors and a base for slidably supporting the rails, the combination of a pair of spaced, substantially horizontal baiiles under saidbase, an air heater under oneiof said baies, a fan under said-one of said baffles, and means forming an air passage including said web, the space between said baflies, said heater and said fan in series, said fan recirculating air through said passage, and air sealing plates attached to said rails and contacting said baies for preventing the escape of air from said passage between saidrails and baffles.

3. In a tenter frame, web drier having a housing containing spacedconveyors for carrying a web to be dried through the drier, rails for supportingV the conveyors and a base for-'slidably supporting the rails, the combination of a-pair of spaced, substantially horizontal baiiles vunder said base, Ymeans forming an air seal between said rails and bafes, an air heater under one conveyors for carrying ay fan in series, said fan recirculating air through said passage, air sealing plates attached to said vrails and contacting said bafes for` preventing the escapel of air from said passage betweenv said rails and bailies and means including adiustable damper means providing a by-pass around said web fora portion of the recirculated air.

5. In a tenter frame, 'web drier having a housing containing spaced conveyorsrfor carrying a web to be dried through the drier, rails for supporting the conveyors and a base for slidably supporting the rails, the Vcombination of a pair ofv spaced, substantially horizontal baffies under said base,.means forminglan air seal between said rails and baflies, an air heater under one ofsaid baflies, a fan under said one ofsaid baffles, and means formingfan air passage including said web, the space between said baies, said heater and said fan .in series, saidrian recirculating air through said. passage, and means including a counter-balanced damper providing a by-pass around said web for a portion of the recirculated air. v I Y 6'. In a tenter frame, web drier having a housing containing spaced conveyors for carrying a web to be driedthrough the drier, rails for supporting the conveyors and a base for slidably supporting. the rails,J the combination of a pair of spaced, substantially khorizontal bales under said base, an air heater under one of said bailies, a fan under saidone of saidbafes, and means forming an air passage including said web, the space between saidibaiiles, said heater and said fan in series, said fan recirculating .air through said passage, airsealing `plates attached to said rails and contacting said baiesfor preventing the escape of air from said passage between said rails and baffles, and means including a counterbalanced damper providing a by-pass around said web for a portion of the recirculated air.

7. In a tenter frame, web drier havingA a housing with side wallsand a roof, said housing containing spaced conveyors forv carrying a web to be dried through the drier, rails for supporting the conveyors and a ybase forslidably supporting the rails, said base being spaced from said side walls, the combination of a pair of spaced, substantially horizonta1 baiilesspaced from said side walls vunder said base, an air heater under one of said baffles, a fan under said one of said baflies, means forming a recirculated air passage including said web, the. space between said baffles, said heater, said fan, the spaceV between one of said sidewalls and said base, and the space between saidroof and said web, means forming a passage between said base and the other of said walls for a 'portion of. the recirculated air ina path bypassing said web, a damper in said last mentioned passage, and means forming an air seal between said rails and bafes.

8. In a tenter frame, web drier having a housing with side walls and a roof, said housing containing spaced conveyors for carrying a web to be dried through the drier, rails for supporting the conveyors and a base for slidably supporting the rails, said base being spaced from said side walls, the combination of a pair of spaced, substantially horizontal baffles spaced from said side walls under said base, an air heater under one of said baiiies, a fan under said one of said baiiies, means forming a recirculated air passage including said web, .the space between said baffles, said heater, said fan, the space between one of said side walls and said base, and the space 'between said roof and said web, means forming a passage between said base and the other of said walls for a portion of the recirculated air in a path bypassing said web, a counterbalanced damper in said last mentioned passage, and means forming an air seal between said rails and baiiies.

9. In a tenter frame, web drier having spaced conveyors for carrying a web to be dried through the drier, having rails for supporting the con,- veyors and having a base for slidably supporting the rails, said b-ase being spaced from the side walls of said drier, a pair of spaced, substantially horizontal bales under said base, an air heater under one of said baffies, a fan under said one of said baffles, said fan recirculating air through said web, the space between said bafes, through said heater, the space between one of said side walls and said base, and the space between the roof of said drier and said web, means forming al passage between said base and the other of said walls for a portion of the recirculated air in a path by-passing said web, a damper in said passage, and air sealing plates attached to said rails and contacting said baiiies.

10. In a tenter frame, web drier having spaced conveyors for carrying a web to be dried through the drier, having rails for supporting the conveyors and having a base for slidably supporting Ithe rails, said base being spaced from the side walls of said drier, a pair of spaced, substantially horizontal baies under said base, an air heater under one of said baiiles, a fan under said one of said baiiies, said fan recirculating air through said web, the space between said bafes, through said heater, the space between one of said side walls and said base, and the space between the roof of said drier and said web, meansforming a passage between said base and the other of said hwalls for a portion of the recirculated air in a path by-passing said web, a counter-balanced damper in said passage, and air sealing plates attached to said rails and contacting said baiiies.

MILTON E. HANSON. 

